I have perfect service where I live, but whenever I'm on the phone, eventually everything goes silent and they can't hear me and i can't hear them so i have to hang up and call back
Hi, it could be an issue with your service or it could be an issue with your phone. I would look into dealing with the former first to rule out any sim card issues before you start looking at the phone.
Speak to your service provider and see if they can assist.